The Airports Commission has finally published its report on UK airport capacity,emphatically supporting a third runway at Heathrow over its rivals – a Gatwick second runway or the Heathrow Hub option (a runway on the end of one of Heathrow’s existing runways). The Commission’s recommendation for a third runway did come with the conditions of ending night flights and £1 billion needed for compensation. Both of these sweeteners will more than turn a few heads in West London to the possibility of a third runway. However, they also serve to draw attention from the environmental impacts the Commission doesn’t have an answer for.

To start with the Airports Commission has not placated concerns about aircraft noise which is the source of the vocal political opposition to Heathrow expansion (Heathrow currently has the rather dubious award of “most people affected by aircraft noise in Europe“). Rather than accepting that more flights would mean more aircraft noise, the Airports Commission has opted to disproportionately shift the noise to communities that are currently not over flown. According to the Commission’s own assessment, some 320,700 would have planes over their heads for the first time with a new runway. What’s important is that many of these people are simply unaware of the storm heading their way. Fortunately, a group of London MPs are trying to highlightthis issue.

Secondly, there is the very relevant issue of air quality, which was one of the main reasons that the Blair/Brown Labour Government was unable to advance plans to build a third runway, despite being fully behind it. Yet, the Airports Commission is still unable to say with any conviction whether a new runway could be built without continued breaches in the legal limit of air quality.

The Commission describes the air quality impact of a third runway as “significantly adverse”. Considering the Government estimates that the area around a two runway Heathrow will have the second highest levels of air pollution in the country by 2030, a third runway would move it into first place (another award Heathrow could add to its collection).

The Airports Commission of course says that the air quality impact could be reduced through various measures. However, the Commission’s consultants concluded that it “isn’t clear” whether Heathrow’s promise to not increase the number of cars accessing the airport is deliverable. The Commission then puts a lot of faith in an ambitious new Government plan to tackle air quality. We should find out whether this is vindicated in early 2016.

Finally, there is the small concern about meeting our national climate targets. Sir Howard Davies evidently gristles every time that CO2 emissions are mentioned. This was perhaps no more evident than when he deflected a question on managing CO2 emissions at the final report launch to a colleague of his. Sir Howard’s lack of interest in all things climate related also appears to represent the Airports Commission’s approach to the issue.

There is a recommended limit to the level of CO2 emissions from aviation that can be allowed in 2050 so that the UK as a whole can stand a chance of meeting its national climate change commitments. Unfortunately, the emissions from an expanded Heathrow on top of those from other airports will far exceed that limit according to the Airports Commission.

The Government’s advisors on climate change say exceeding that limit isn’t an option and so aviation emissions will have to managed somehow. The good news is that according to the Airports Commission managing demand is possible with a new runway. The bad news is that the cost of emitting a tonne of carbon dioxide would have to rise from around £5 today up to somewhere in the region of £300 per tonne in 2050 (or even up to £1050 in some scenarios). That would mean increases in ticket prices of around £500 for a return flight to New York, or in other words an end to the “democratisation of air travel“.

Rather than comment on the feasibility of such a policy, the Airports Commission has left the challenge to the Government. Incidentally, Heathrow could also retain another award with a third runway. In 2012, it was the airport responsible for most CO2 emissions in the world. To have any chance of keeping hold of that award it will need to expand to keep up with the likes of Dubai and Istanbul.

So today’s announcement may change the views of some people on Heathrow expansion, but in no way have the environmental challenges been addressed. Now it is over to the Government.